title: Does change in distress matter? Mechanisms of change in prolonged exposure for PTSD.
abstract: OBJECTIVE
  Clinically, many individuals persist in prolonged exposure therapy (PE) for chronic PTSD despite continuing distress during recounting of the trauma memory (imaginal exposure). Theorists suggest that distress reduction is necessary for successful treatment outcome (e.g., Foa & Kozak, 1986), while others suggest otherwise (e.g., Craske et al., 2008). This study examined clinically reliable changes in distress, relations to broad clinical outcomes, and whether homework adherence affected this relationship.
  
  
  METHODS
  In 116 patients with PTSD, first to last imaginal exposure sessions' peak and average distress was examined, calculating reliable change in distress. Homework adherence and helpfulness were examined. At post-treatment, PTSD symptoms (re-experiencing, avoidance, hyperarousal), depression, and functioning were examined.
  
  
  RESULTS
  Patients exhibited a lack of reliable change in distress (64.7%) more than a reliable change in distress (35.3%). Although no difference in post-treatment PTSD diagnostic status, individuals experiencing a reliable change in distress reported lower PTSD severity (re-experiencing, hyperarousal), depression, and better functioning. Further, perceived helpfulness of imaginal homework had an indirect effect on this relationship.
  
  
  CONCLUSIONS
  This study did not utilize a distress tolerance self-report measure; however, examined self-reported distress during imaginal exposure.
  
  
  CONCLUSIONS
  Results are encouraging for clinicians treating PTSD with PE, arguing that lack of reliable change in distress to the trauma memory does not result in treatment failure. Patient "buy in" to homework, rather than amount completed, was related to the process of distress reduction. Results suggest that distress reduction in imaginal exposure is not a key mechanism underlying therapeutic change in PE.
authors.affiliation: University of Washington, Department of Psychology, Box 351525, Seattle 98195-1525, USA. Electronic address: ejbluett@aggiemail.usu.edu.
authors.forename: Ellen J
authors.initials: EJ
authors.lastname: Bluett
authors.forename: Lori A
authors.initials: LA
authors.lastname: Zoellner
authors.forename: Norah C
authors.initials: NC
authors.lastname: Feeny
mesh_terms: D000328:Adult; D001007:Anxiety / Q000175:diagnosis / Q000209:etiology; D003863:Depression / Q000175:diagnosis* / Q000209:etiology*; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D007171:Implosive Therapy; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D015203:Reproducibility of Results; D013313:Stress Disorders, Post-Traumatic / Q000150:complications* / Q000534:rehabilitation*
keywords: Distress; Homework; PTSD; Prolonged exposure; Reliable change; Treatment outcome